/* xxx.css */
.stack-parent {
    width: 400px;
    height: 400px;
    margin: 50px;
    background-color: #ffffff;
    border-width: 1px;
    border-style: solid;
}

.back-child {
    width: 300px;
    height: 300px;
    background-color: #3f56ea;
}

.front-child {
    width: 100px;
    height: 100px;
    background-color: #00bfc9;
}

.positioned-child {
    width: 100px;
    height: 100px;
    left: 50px;
    top: 50px;
    background-color: #47cc47;
}

.bd-radius {
    border-radius: 16px;
}